Cassandra Java Example

CassandraExample.java

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package mb.learningcurve.Cassandra;

import com.datastax.driver.core.Cluster;
import com.datastax.driver.core.ResultSet;
import com.datastax.driver.core.Row;
import com.datastax.driver.core.Session;

/**
 *
 * @author mb
 */
public class CassandraExample {

    private Cluster cluster;
    private Session session;
        
    public static void main(String[] args) {
        CassandraExample c = new CassandraExample();
        
        c.createSchema();
        c.mainFunction();
    }
    
    public void mainFunction(){
        

        session.execute("INSERT INTO users (lastname, age, city, email, firstname) VALUES ('Jones', 35, 'Austin', 'bob@example.com', 'Bob')");

        // Use select to get the user we just entered
        ResultSet results = session.execute("SELECT * FROM users WHERE lastname='Jones'");
        for (Row row : results) {
            System.out.format("%s %d\n", row.getString("firstname"), row.getInt("age"));
        }

        // Update the same user with a new age
        session.execute("update users set age = 36 where lastname = 'Jones'");
        // Select and show the change
        results = session.execute("select * from users where lastname='Jones'");
        for (Row row : results) {
            System.out.format("%s %d\n", row.getString("firstname"), row.getInt("age"));

        }

        // Delete the user from the users table
        session.execute("DELETE FROM users WHERE lastname = 'Jones'");
        // Show that the user is gone
        results = session.execute("SELECT * FROM users");
        for (Row row : results) {
            System.out.format("%s %d %s %s %s\n", row.getString("lastname"), row.getInt("age"), row.getString("city"), row.getString("email"), row.getString("firstname"));
        }

        // Clean up the connection by closing it
        cluster.close();
    }
    
    public void createSchema() {
        cluster = Cluster.builder().addContactPoint("127.0.0.1").build();
        
        session = cluster.connect();
        
    session.execute("CREATE KEYSPACE IF NOT EXISTS demo WITH replication "
            + "= {'class':'SimpleStrategy', 'replication_factor':1};");

    session.execute("CREATE TABLE demo.users (" + "lastname text PRIMARY KEY,"
            + "age int," + "city text," + "email text,"
            + "firstname text" + ");");
            
        session = cluster.connect("demo");
}
}